Advances in technology have led to substantial changes in the design of automobiles, particularly with respect to alternative fuel vehicles, such as hybrid, electric, and fuel cell vehicles. Such vehicles may use an electric drive system in which an electric motor is powered by a battery to produce torque for a drive shaft. An electronic control system controls the operation of the electric motor by evaluating the torque requirements needed for operating the vehicle and generating a torque command for driving the vehicle.
During operation, the electric drive system may generate heat, which is usually dependent on the amount of torque generated by the electric drive system. If not properly considered, excess heat may result in undesirable issues. As such, torque commands are conventionally limited by predetermined torque capabilities of the electric motor that are based on the voltage level of the battery and other operating characteristics. These torque capabilities are generated by considering the long term impact of the torque on the vehicle, generally according to the expected life of the vehicle. Since the torque capacities function as a limit the torque command, selection of the torque capacities also impacts the performance of the vehicle. In general, designers are continually attempting to increase the performance of the vehicle without adversely impacting the electric drive system or substantially adding to the complexity and power usage.
Accordingly, it is desirable to improve performance of the electric drive system without substantially increasing processing complexity and power usage. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.